astrostart im gmsd 1 manual

A customer brought in 05 Montana SV6 which he says has a factory remote starter. It also looked like there was an Astrostart installed, but when I tried to gain access to main module to program a new Astrostart remote, all I found was an Astrostart IM-GMSD-1 interface installed. I can't find much info on it online but it looks like it is just a door lock interface except for the fact that it has an antenna plugged into it. Does this unit control the factory remote starter? If so, does anyone have the manual or know how to program a remote? Thanks

In case anyone ever searches for this module because they need to program a remote to it, ground the Dk. Blue wire until the LED flashes 2x, then press lock on the transmitter and the LED will blink 1x. I think you need to hit the lock 4x for it to work. The LED will flash 1x each time it is pressed.